Toxic Chemicals Found in Drinking Water Of 7 Million Californians

Potentially dangerous chemicals have contaminated the drinking water sources serving 7.5 million Californians, according to a report by an environmental advocacy group.

Using data from California water system tests mandated by the Environmental Protection Agency between 2013 and 2019, the Washington, D.C.-based Environmental Working Group found that 74 of California's community water systems contained potentially dangerously high levels of toxic chemicals called PFAS.

Low doses of PFAS chemicals in drinking water "have been linked to an increased risk of cancer, reproductive and immune system harm, liver and thyroid disease, and other health problems," the EWG report said. PFAS are known as "forever chemicals," because they never break down after being released into an environment.

More than 40 percent of the water systems where PFAS chemicals were found had at least one sample exceeding 70 parts per trillion — the level at which the EPA issues drinking water advisories. And all of California's systems exceeded 1 part per trillion, EWG's preferred standard which has been recommended in some independent studies.

The drinking water utilities with the highest detections of PFAS include Camp Pendleton, Corona, Oroville, Rosemont and other Sacramento suburbs, according to EWG's data. Click here to see the full list of detections.

Since the data was collected over several years, EWG's data doesn't necessarily reflect the current levels of contamination in each system. Instead, it shows "a snapshot of what was in the water when it was tested," the report said.

Some water systems may have already stopped using contaminated wells, blended the contaminated water with cleaner sources or installed water treatment to reduce the levels of PFAS. In 2017, for example, Camp Pendleton issued a water quality report saying it had shut down a well showing excessive levels of PFOA and PFOS — two of the dangerous PFAS chemicals.

More than 800 communities across the U.S. have been found to have PFAS contamination, the EWG report said, but neither the EPA nor the state of California have set a legal limit for PFAS in drinking water.

Sources of PFAS contamination include firefighting foams, industrial discharge of PFAS into the air and water and PFAS in food packaging and other consumer products.